Device for sterilizing and cooling liquids



March 25. 1941. DE JQNGE 2,236,470

DEVICE FOR STERILIZING AND COOLING LIQUIDS Original Filed Feb. 18, 1935Patented Mar. 25, 1941 UNITED STATES 2,236,470 DEVICE ron STERJLIZINGAND COOLING LIQUIDS Leonardus de Jonge, Rotterdam, Netherlands,

assignor to the Syndicate Jozijdhoif, Rotterdam, Netherlands,constituted by the members: George Jacob van Ziiderveld, Jr., GeorgeJacob van Zijderveld, Sr., Johannes van 't 1101!, and

Leonardus de J onge Original application February 18, 1935, Serial No.

Divided and this application May 10,

1938, Serial No. 207,138. In the Netherlands February 20, 1934 i 1Claim.

My invention relates to apparatus for sterilizing putreflable liquidsunder pressure.

This application is a division of Ser. No. 7,143 filed February 18,1935, Patent No. 2,173,411 issued Sept. 19, 1939.

In the known apparatus for the sterilization of putreflable liquids,particularly of milk, the liquid is conducted through a heating element,comprising a plurality of narrow tubes together form- 0 ing a singleconduit, the said tubes being housed in a casing provided with a feedline and a discharge line for the heating medium and, having a coolerconnected with the heating element, and brought from room temperature toa high temperature within a very short time.

With these apparatus, however, one is not certain that the liquid isreally exposed for a sufficient period to the higher temperatures whichare absolutely necessary for killing the spores, so

that there always remains the possibility of obtaining a non-sterileproduct. This uncertainty is entirely removed by the application of theapparatus according to my invention.

For this purpose the novel apparatus com- 2 prises at least two heatingelements, the supply of the heating medium to each of the said elementsbeing separately adjustable, and the individual tubes in each heatingelement being mutually connected by means of comparatively wide mixingchambers. In this manner the liquid after leaving each heating tube andbefore it enters into the next heating tube, is given a whirling motion,which causes the entire mass of liquid to obtain the same temperature.

' In the known sterilizing apparatus, on the contrary, the individualheating tubes are either connected by means of bent pieces having thesame diameter, which makes that the core of the flow of liquid alwaysremains in the same place and consequently receives the least share ofthe heat,

so that the same temperature will not be present in all parts of theflow of liquid, or by grooves formed in the end members of the casinghousing the narrow tubes.

The said whirling motion may still be promoted in the apparatusaccording to my invention by providing in the mixing chambers a pointedprojection opposite to and located in the axis of the heating tubes.

With the apparatus according to my invention it is possible tocompletely sterilize within a short time by a single treatment the mostwidely varying kinds of beverages such as beer, lemonade, cider, fruitjuices, milk, cream, skimmed milk, etc. so that they will retain theiroriginal taste, color and composition as with said apparatus it becomespossible to individually regulate the temperature in the separateheating elements by means of the adjustable supply of the heating mediumto each element. In this Way 5 the liquid to be sterilized is certainlysubjected for a suflicient long period of time to the elevatedtemperatures.

My invention will now be further explained with reference to the drawingwhich by way of 10 example represents an apparatus for sterilizing milkand milk products.

In the said drawing Fig. 1 represents a view of the apparatus accordingto my invention, part of it being .a ver- 15 tical cross section,

Fig. 2 is a view according to the line II-II in Fig. 1 the closing piecebeing removed and Fig. 3 is a similar view according to the line III-IIIin Fig. 1 and 20 Fig. 4 represents a detail on a somewhat enlargedscale.

The apparatus according to Fig. 1 contains three heating elementscomprising passages I, for example tubes of a large diameter in which 25are located the narrow heating tubes 8. The said passages I are eachconnected with a steam supply tube 21 by means of the branch tubes 2, 3,4 and with a steam exhaust pipe 28 by means of the branch tubes 5, 6,the said branch tubes 30 2, 3, 4 each being provided with a cook; orfaucet. By adjusting the said cocks it is possible to regulate thesupply of steam to the heating elements and consequently theirtemperature. The

diameter of the tubes 8 in the present case is 11 35 millimetres.

The outlet ends of the heating tubes 8 open into mixing chambers 9 towhich the next tube is connected, so that the liquid to be sterilized isgiven a whirling motion in the said mixing 4o chambers and willcirculate through the tubes along a tortuous path. The mixing chambersare closed by two common closing pieces I0 and H in which latter closingpiece there is provided a supply tube 12 for feeding the liquid to becooler through a tube l8. The closing member H is provided with'an airevacuation cock or faucet l9 and with a discharge tube 20 for the cooledliquid. The said tube 20 is provided with a pressure regulating valve 2|and with a safety valve 22. The complete apparatus is housed in a casing25. In order to promote the whirling motion in the mixing chambers 8projections 26 may be provided on the closing plates Ill and II oppositethe mouths of the tubes 8.

Such a projection is represented on a somewhat enlarged scale in Fig. 4in which the preferably sharp point of the projection is located exactlyin the axis of the tube 8. The whirling motion produced by thisprojection is indicated in the figure by the arrows.

The mixing chambers 9 are of the configuration shown in Figures 2 and 3.Referring to these figures the tubes 8 are provided with arrowsindicating the flow of milk. Each mixing chamber 9 has a tube leadingmilk thereto and a tube leading milk therefrom. The mixing chamber l3 ofthe cooler I4 is shaped as shown in Fig. 2 with one tube 8 leading milkthereto and five tubes l6 leading milk therefrom. The opposite mixingchamber is shaped as shown in Fig. 3 at the top thereof and the milk inthe tubes l6 flows toward the observer as indicated by the arrows.

Therefore as clearly indicated in Figs. 2 and 3 the milk coming from thesupply tube l2 flows through the lowermost tube 8 from right to left asshown in Fig. 1 and then returns through the tube 8 connected to thelowermost tube 8 by the lower mixing chamber 9 as shown in Fig. 2. Thecourse of the milk through the sterilizer is easily followed byreferring to the arrows shown in Figs. 2 and 3.

After the entire apparatus has been sterilized first, for instance bymeans of steam, fresh steam, e. g. under a pressure of about 8atmospheres is introduced into the passages l. The milk to be treated isthen pressed likewise under a pressure of about 8 atmospheres into thetube l2 and will then flow with a great velocity of approximately 6metres per second through the tubes 8.

The said tubes are each having a length of about 3.25 metres here, sothat the milk will have flowed through the entire tube system 8 inapproximately 8 seconds. The steam supply to the three passages I isregulated so that the temperature of the milk after leaving the lasttube 8 of the lower heating element will be about 135 C. against about145 C. upon leaving the last tube 8 of the intermediate heating elementand about 150-160 C. after leaving the last tube of the upper heatingelement. The said temperatures may be read from the thermometers placedin the relative mixing chambers, one of which thermometers is denoted inthe drawing by 23. In the same manner the pressure in the mixingchambers and at the end of the cooler may be read from recordingpressure gauges. The last recording pressure gauge is indicated in thedrawing by 24.

When the pressure under which the milk is fed to the tube system throughthe tube I2 is as high as about 8 atmospheres the pressure regulatingvalve 2| in the tube 20 is adjusted so that at the end of the cooler thepressure will be about 6.5 atm.

In the tube system 8 the milk consequently is only for a few secondsexposed to the temperature required for completely killing all germs andspores, which in the case of milk preferably is as high as 140-160" C.,but which always must be above 130 C.

In the cooler H the milk is cooled to about 80 C. and finally filledinto sterilized bottles through the pipe line 20 connected to the feedline of the filling device. Milk treated in this manner will keep for anindefinite period of time without spoiling.

For sterilizing other liquids, such as, e. g. beer, heating to a lowertemperature, for instance to about 90-l00 C. will be suflicient and thetube system may be smaller in length, so that two heating elements willsufflce.

It is obvious that it is necessary for beer and other beveragescontaining carbonic acid cooling is to be eifected down to a temperatureof about C., in order to prevent" the carbonic acid present in thebeverage to start efi'ervescing and being lost during filling.

It is an especially surprising feature that according to my presentinvention cream and even skimmed milk may be perfectly sterilizedwithout any detriment.

I claim:

An apparatus for sterilizing putreflable liquids by means of heatcomprising a plurality of outer tubes, a plurality of inner tubeslocated within said outer tubes, each of said outer tubes having acontrollable inlet and outlet for a heating medium, relatively spaciouschambers interconnecting said inner tubes, and pointed projections insaid chambers positioned at substantially the axes of said inner tubesfor promoting a whirling motion in the liquid passing therethrough.

LEONARDUS on J ONGE.

